Brake question!

[JerseyHick]

Please help! The brakes on my M135 are driving me crazy..
Heres what I got...
.new master cylinder
."rebuilt" air pac, I purchased, that HISS'S air continuously. But seems to work OK.
.pulled and wheel cylinders, cleaned and honed the OK looking ones.
.replaced 6 wheel cylinders that were beyond repair.
What it does..
I bleed out the system works perfect all day. But, if it sits overnight, when I apply the brakes. Pedal goes all the way to the floor, as if theirs air in the system.. Bleed out again, they work perfect again.
Now when it sits for long periods of time, looks as if some wheel cylinders leak slightly. My fault, shoulda replaced them all.
Any ideas where the air may be comming from?
I know it's tuff to diagnose from a description. But im tired of throwing money at these brakes!
Thanks
!

 

[m1010plowboy]

It's a tight system once it works. No leaks sits for weeks.

The air-pak is a re-build item if it's been sitting or it can allow air into the 'fluid' system each time you run. hssssss gurgle gurle

1) Any fluid coming out of your air-tanks when you drain them?

There is a maintenance procedure to remove a line and lube the internal organs of the air-pak and is a starting point buttt, it's nice having them on the bench for a tear-down.

Once you get them right, you're done!

 

[tburk49760]

I've seen similar issues on other rigs. If the shoes aren't adjusted properly, the pedal travel becomes an issue. After sitting, the springs force the fluid back to the mc. First several pedal presses the next morning are just getting the shoes back to the drum.

 

[jerseyjeep2003]

Please help! The brakes on my M135 are driving me crazy..
Heres what I got...
.new master cylinder
."rebuilt" air pac, I purchased, that HISS'S air continuously. But seems to work OK.
.pulled and wheel cylinders, cleaned and honed the OK looking ones.
.replaced 6 wheel cylinders that were beyond repair.
What it does..
I bleed out the system works perfect all day. But, if it sits overnight, when I apply the brakes. Pedal goes all the way to the floor, as if theirs air in the system.. Bleed out again, they work perfect again.
Now when it sits for long periods of time, looks as if some wheel cylinders leak slightly. My fault, shoulda replaced them all.
Any ideas where the air may be comming from?
I know it's tuff to diagnose from a description. But im tired of throwing money at these brakes!
Thanks
!

When I was chasing brake issues on mine, I discovered the vent line that comes up on the firewall near the air filter has an orificed fitting on the end that was clogged up. This wouldn't allow the air pack to vent properly and forced air into the master cylinder. I also had a "hiss", but mine hissed around the cap on the MC. It also drove me crazy, as sometimes the brakes worked and other times the pedal would go to the floor until I would pump it up. Try cleaning that orifice fitting. PM me, I live pretty close to you..in Gloucester City.

 

[JerseyHick]

Thanks jersey jeep.
I actually disconnected the vent line. No luck.
No matter, took truck out today and, I think, head gasket let go!
Never owned a vehicle like this. Its one thing after another with this truck.
May be parting it out soon.. I'll post what I have.
Thanks again.

 

[Section8]

Don't give up on er yet! Head gaskets should be fairly easy to get still since a lot of hot rodders use these motors for their cars. The head should be fairly easy to work on as well since the engine design is pretty strait forward.
If you were gonna part her out its to bad I aint a millionare and am so far away! I would buy the whole rig off your hands!
Seems frustrating right now but a weekend doing the head and you will be smiling as you drive down the road having every one looking in awe at your awesome rig!

 

[m1010plowboy]

Its one thing after another with this truck.

That's the best G749 description ever! The lube chart alone is enough to beat the hardiest builders down. We've got your six so whatever you decide to do with her, tell us if we can help.

It's obvious now your trucks a lady.

 

[swbradley1]